Lock extension unit



July 22, 1941- w. R. SCHLAGE 2,250,036

` Loox EXTENSION UNIT Filed June 7, 1939 2 sheets-sheet 1 es 27 C 2G 25 i IN V TOR.

wam 7? aia ATTORNEY July 22, 1941. w. R. SCHLMaE` 2,250,036

LOCK EXTENSION UNIT Filed June 7. 1939 2 Sheets-Sheet 2 I N V EN TOR.

ATTORNEY.

Patented July 22, 1941 LOCK EXTENSION UNIT Walter R. Schlage, Burlingame, Calif., assigner to Schlage Lock Company, San Francisco, Calif., a corporation of California Application June 7, 1939, Serial No. 277,768

2 Claims.

This invention relates to an extension unit whereby the backset of a lock unit when installed in a door may be materially increased.

Backset is a term used in the door lock and building industry, and refers to the measurement or distance between the edge of Ithe door and the center of the lock spindle. The average backset on inside doors is 21/2 inches, and the backset on outside or so-called front doors, 23/4 inches. Architects and builders are constantly attempting to make innovations, that is, introduce new features, novelties, new designs, etc., and recently it has become the Vogue in certain types of buildings and other structures materially to increase the backset in door locks. In some instances this is carried to such an extreme as to position the spindle and knobs approximately at the center of a door.

In certain types of lock, for instance in the so-called mortise type, the latch bolt and the latch bolt actuating mechanism, to wit, the spindle, the rollback member, the knobs, etc., are carried by a single housing. To increase the backset in that type of lock it would be necessary to increase the length of the housing and of much of the mechanism within the housingobviously, a very costly procedure. `There is another type of door lock which is divided into two separate units, each enclosed in its own housing. 'I'hese units are known as the latch bolt unit and the latch bolt actuating unit. In this type of lock, increase of the backset has been accomplished by lengthening the housing and contained mechanism of the latch bolt unit. 'Ihis is also costly and is not very satisfactory, and it compels the lock manufacturer to furnish the latch bolt unit in varying lengths depending upon the backset desired.

Whether the housing and mechanism of the mortise type of lock is lengthened, or the latch bolt unit of the latter type of lock is lengthened, the cost to the lock manufacturer is excessive; and besides that, a considerable stock of locks of varying lengths must be carried to meet the specific measurements and lengths demanded by different architects and builders.

'Ihe object of the present invention is to improve locks of the two-unit type, that is, in which the lock mechanism consists of two separable units, to wit, a latch bolt unit and a latch bolt actuating unit; and particularly, to provide an intermediate or extension unit, insertable between the latch bolt unit and the latch bolt actuating unit, whereby any backset may be obtained without change or increase of the length of either of the first named units.

The invention is shown by way of illustration in the accompanying drawings, in which Fig. 1 is a central longitudinal vertical sectionl taken through the type of lock heretofore referred to, which is known as a two-unit lock, the section showing the intermediate or extension unit in 'position between the aforementioned units;

Fig. 2 is a similar section showing the invention applied to a door lock employing a deadlocking latch or bolt;

Fig. 3 is a longitudinal horizontal section, taken at right angles to Fig. 1 or 2, of the extension or intermediate unit;

Fig. 4 is a perspective view of the retractor bari' carried by the extension or intermediate un t;

Fig. 5 is a perspective view of the latch bolt actuating unit;

Fig. 6 is a perspective view of the extension or intermediate unit;

Fig. 7 is a perspective view of the latch bolt unit; and

Fig. 8 is a fragmentary perspective view of a door, showing the manner in which it is bored and otherwise prepared for the reception of the type of lock shown in Figs. 5, 6, and 7.

The type of door lock mechanism to, which the present invention appears most readily applicablel is the separable type, that is, a lock in which the latch bolt mechanism is contained in one housing or unit and the latch bolt actuating mechanism in another housing or unit, the two housings with their enclosed mechanism being separably insertable in a door when installing the lock. In order that the extension unit forming the subject matter of this application may be fully understood, a brief description of the latch bolt unit and the latch bolt actuating unit will be submitted.

The latch bolt unit (see Figs. 1 and 7) comprises a face plate 2 which is adapted to be secured to the outer edge 3 of a door A by means of screws 6. 'Ihe face plate has an opening formed therein through which the latch bolt l extends in the usual manner. Secured to the rear side of the face plate is a cylindrical elongated housing 8; the rear or inner end of this housing is closed by an end plate 9, but this plate has an opening therein, which forms a guide and permits the inner end of a retractor bar I0 to extend therethrough. The forward end of the bar is secured to the latch bolt l; hence when a pull is exerted on the retractor bar the latch -bolt will be retracted. Conversely, when a pull is not exerted, a spring II interposed between the latch bolt and the end plate 9 will maintain the latch bolt in extended position.

The latch bolt actuating unit is generally indicated at B (see Figs. 1 and 5). It comprises a housing I4, which is materially larger in diameter than the latch bolt housing. Extending through the housing and journaled therein is a spindle I5, and formed on the spindle is a rollback member I6, which imparts reciprocal movement to a retractor I'I when the spindle is rotated. The retractor is provided at its forward end with a pair of spaced fingers I8 which under normal conditions engage a. pair of lugs I9 formed on the inner end of the retractor bar I8. This normal condition will exist as long as the standard backset, for instance 21A; inches, is employed, but where the backset is increased, en-

gagement between the fingers I8 and the lugs I9 can obviously not be maintained, unless the latch bolt, retractor bar I8, and housing 8 are proportionately lengthened. This of course is not feasible from a manufacturing point of view, and is the main reason for providing an extension or intermediate unit, generally indicated at C, which may be interposed between the latch bolt unit and the latch bolt actuating unit.

The extension or intermediate unit is best i1- lustrated in Figs. 1 and 6. It comprises an elongated cylindrically-shaped housing 28 having the same diameter as the latch bolt housing 8. One end of the housing 20 is open, and is provided with a pair of in-turned lugs 2|, while the other end is provided with a pair of outwardly-turned lugs 22. 'I'he end of the housing adjacent lugs 22 is closed by a disc 23. A second disc 24 is mounted within the housing, and this disc, together with the disc 23, serves as a support and guide for an extension retractor bar 25 which is best shown in Figs. 1, 3 and 4. The disc 24 is secured on the bar 25 intermediate its ends, and as this bar is slidably mounted within vthe housing, so is thedisc 24. A spring 2B surrounds the bar, and is interposed between the discs 23 and 24, and as disc 23 is permanently secured in the housing, while the disc 24 and the bar to which it is secured are slidable, the spring tends to urge the bar in the direction of arrow a (see Fig. l) Such movement is, however, limited, as stop-lugs 21 (see Fig. 3) are provided. The rear or inner ends of the extension retractor bar 25 extends through the disc 23 and is provided with a pair of lugs I 9a substantially identical to the lugs I9 formed on the inner end of the bar I8, which, as previously stated, is the retractor bar whereby the latch bolt I is retracted. The opposite or forward end of the bar 25 is provided with a pair of fingers I8a, which serve the same function as the fingers I8 of the main retractor Il.

In actual practice, when a lock of this character is to be installed in a door, two holes must be drilled with a wood bit or similar tool. One hole (see Fig. 8) is bored transversely through the door, as indicated at 38, and receives the latch bolt actuating unit indicated at B. The other hole 3| is drilled through the edge of the door in a direction at right angles to the rst hole, and this hole serves the function of receiving the intermediate unit C and the latch bolt unit shown in Fig. '7. The distance between the edge of the door and the center of the hole 38 depends upon the backset desired, and may 1n extreme instances be great enough to place the hole substantially in the center of the door. In this particular instance let it be assumed that a backset of six inches is desired. If that is the case, the extension or intermediate unit will have to be approximately 31/2 inches long, as the normal backset is 21/2 inches. If the backset on another door is to be eight inches, the extension unit will have to be 51/2 inches long. These dimensions are merely submitted to bring out the fact that the length of the extension unit varies; that is, the manufacturer, instead of changing the standard dimensions of the latch bolt units, merely supplies extension units of varying lengths, and will under normal conditions have a suiiicient number of different lengths on hand to take care of current demand.

When a door has been bored and the face countersunk for the reception of the face plate 2 of the latch bolt actuating unit, as clearly shown in Fig. 8, the installation of the lock will be accomplished as follows: The latch bolt unit 'I and the intermediate or extension unit shown in Fig. 6 are rst connected end to end, that is, the adjoining ends shown in Figs. 6 and 7 are connected. This is accomplished by providing an opening 36 in the side and forward end of the intermediate unit C; through this opening lugs I3 formed on the inner end of the retractor bar I8 of the latch'bolt unit are inserted, then by moving the latch bolt unit laterally with relation to the intermediate unit, or vice versa, the lugs will pass behind and under the fingers I8a formed on the forward end of the retractor bar 25. At the same time the in-turned lugs 2| formed at the forward end of the housing C of the intermediate unit will psss behind outwardlyturned lugs 2Ia formed on the inner end of the latch bolt unit, the interlock between the several lugs and fingers being clearly shown in Fig. 1. By this method of interlock the retractor bars I8 and 25 are connected, and so are the two housings of the respective units. With the two units thus connected, it is only necessary to insert them endwise through the opening 3I formed in the door, and then to secure the face plate by inserting the screws 6. When so inserted, the lugs I9a formed at the inner end of the retractor bar 25 will project a slight distance into the opening 38 formed in the door, and so will the out-turned lugs 22. Hence when the latch bolt actuating unit is inserted endwise through the opening 38, or in a direction transverse of the door, the fingers I8 of the main retractor will pass over the lugs I9a of the retractor bar 25 and engage the same. An interlock between the inner end of the housing 28 of the unit C and the housing I4 of the unit B will also be made, as an opening 31 is formed in the housing I4. This opening serves two functions: first, it permits the inner end of the retractor bar 25-or in other words, the lugs I9a-to extend into the housing I4, where they can be gripped or engaged by the fingers I8; secondly, the opening forms two opposed shoulders 22a, which engage the outwardly-turned lugs 22 formed on the inner end of the housing 28 of the intermediate unit. Thus an interlock is formed between the housings I4 and 28 at one end, and between the housings 28 and 8 at the opposite end. Also, an interlock is formed between the ngers I8 of the main retractor and the inner end of the retractor bar 25, and an interlock is likewise formed between the fingers I8a at the opposite end of the retractor bar 25 and the lugs I9 formed at the inner end of the main retractor bar I8 of the latch bolt unit. Hence, when the spindle is rotated, the rollback member I6 will engage the inner face of the retractor I1, forcing this to move inwardly between guides I1a-formed within the housing I4, and against the tension of a spring I1b. During such inward movement of the retractor I1, fingers I8 engage the lugs I9a of the retractor bar 25. The lingers I8a at the opposite end of the retractor bar engage the lugs I9 of the retractor bar I0, and both bars will thus move in unison in an inward direction with the retractor I1, and thus cause retraction of the latch bolt 1. On the other hand, when the spindle is released, spring I1b will force the retractor I1 in a forward or outward direction. The springs 26 and II will at the same time force the retractor bars 25 and I0 in an outward direction,

vand the latch bolt 1 will accordingly be projected. In other words, a baokset of any' distance desired may be obtained, without in any way altering the construction and operation of the two standard units employed, to wit, thelatch bolt actuating unit and the latch bolt unit, as intermediate units of `any desired length may be furnished whereby a connection is made between the retractor I1 and the retractor bar I0.

In Fig. 1, the extension unit is illustrated in connection with an ordinary door latch. The extension is, however, equally applicable to socalled deadlocking door bolts or latches, as illustrated in Fig. 2. In this type of latch, there is a floating cam plateAll, which is retracted in unison with the main retractor bar, indicated at 4I, when the main latchbolt Ia is retracted by means of the retractor bar 25 and the main retractor I1. This floating cam plate must remain stationary and in the position shown in Fig. 2 when the latchbolt 1a and the deadlocking bolt 1b are depressed. as for instance when a door is slammed or closed, as it is only in this position that the deadlocking of the latch bolt 1acan be elected. If the latch bolt 1a should be depressed while the door is closed, by means of a jimmy or like tool, it would be possible for the cam plate to move with it, due to friction between the cam plate and the retractor bar 4I; and if this happened, the deadlocking mechanism would fail, and the door would be opened. Such movement of the cam plate is, however,

- when an attempt is made to depress it by a jimmy or similar tool. The use of the spring 25 is accordingly important, as it prevents floating of thecam plate except at the times when it should float. If it were not for this factor, the

l spring 26 could be entirely eliminated, as the tension of the latch bolt projecting spring, for instance the one shown at II in Fig. l, is more than sufiicient to actuate not only the main latch bolt 1 or 1a, but also to restore the retractor bar 25 to normal position after actuation.

While certain features of my invention have been more or less specifically described and illustrated, I wish it understood that changes may be restored to within the scope of the appended claims, and that the materialsA and finish of the parts employed may be according to the wishes of the manufacturer or to varying conditions of use.

Having thus described and illustrated my invention, what I claim and desire to secure by Letters Patent is:

1. An extension unit of the character described comprising a tubular housing, a bar slidably mounted therein, a pair of spaced hook-shaped lugs on one end of the bar and bent at right angles thereto, a pair of lugs formed on the opposite end of the bar and on opposite sides thereof, a spring surrounding the bar and urging the bar to move in one direction, and means for limiting the movement of the bar in that direction.

2. An extension unit of the character described comprising a tubular housing, a bar slidably mounted therein, a pair of spaced hook-shaped lugs on one end of the bar and bent at right 'angles thereto, a pair of lugs formed on the opposite end of the bar and on opposite sides thereof, a collar on the bar, a spring surrounding the bar and interposed between the collar and one end of the tubular housing, and stop me s with which the collar engages.

WALTER R. SC GE. 

